1. Field of the Invention
This invention relates to a chassis dynamometer for testing vehicles such as new automobiles in a workshop under normal driving conditions.
2. Description of the Prior Art
FIGS. 1 and 2 illustrate an example of the conventional chassis dynamometers. In this Figures, the numeral 1 denotes rolls, and the numeral 2 denotes a dynamometer connected by a common shaft to the rolls 1. The numeral 3 denotes a base on which the rolls 1 and the dynamometers 2 are mounted. The numeral 4 denotes a vehicle being tested. The numeral 5 denotes a vehicle fastening device. The numeral 6 denotes an engine cooling blower movable in accordance with occasional vehicle positions.
The chassis dynamometer thus constructed operates as follows. The rolls 1 are rotary drums simulating the road surface. The vehicle 4 is locked by the fastening device 5 against fore and aft movement to simulate actual running conditions on the road surface. The driving power of the vehicle 4 is transmitted to the rolls 1 as a rotational force which is transmitted to the dynamometer 2 connected on the same base 3 so that the loadings of the vehicle 4 are absorbed by the dynamometer 2. The loadings on the dynamometer 2 may be equated to those actually met when the vehicle travels on the road so that vehicle running tests can be conducted in a laboratory or workshop without the necessity of actually driving the vehicle.
It is usually desired that the chassis dynamometer mentioned above should be usable not only with a specific vehicle type but also with various vehicle sizes or models subject to a simplified setting procedure.
In the conventional chassis dynamometers mentioned above, when the type of the vehicle to be tested is changed from the front engine front wheel drive vehicle 4a (hereafter mentioned as a F/F vehicle) shown in FIG. 3a to the front engine rear wheel drive vehicle 4b (hereafter mentioned as a F/R vehicle) shown in FIG. 3b, the drive wheel positions on the rolls 1 differ with the F/F vehicle 4a and the F/R vehicle 4b, as shown in FIGS. 3(a) and (b), so that the vehicle positions also differ markedly with different vehicle types, thus making it necessary to provide a spacious laboratory and change the position of the engine cooling blower 6 with different vehicle types. This is inconvenient because the construction of the laboratory may be expensive and a lot of operational time may be involved in changing the setting from F/F vehicles 4a to F/R vehicles 4b and vice versa.